1. Investigación

Isokinetics is a tool commonly used in professional soccer. There is ongoing debate among researchers as to the isokinetic reference values a player should have. Objectives: To determine the absolute peak torque (PT) and average work of professional soccer players in relation to their positions on the field, and to establish the reference values for these variables. Methods: Purposeful sampling was used to select 289 professional soccer players. The sample included 32 goalkeepers, 100 defenders, 98 midfielders, and 59 strikers. The participants were measured preseason. The players were asked to perform a 10-minute warm-up on an exercise bike, and then to perform 5 repetitions at low speed, 10 at medium speed, and 25 at high speed, with 30 to 40-s of rest between each set of repetitions. The contraction method was concentric-concentric in a dynamometer Isomed 2000. Results: The average age, weight, and height of the players was 21.9 years, 74.3 kilograms, and 1.8 meters, respectively. The goalkeepers presented higher PT at the 3 measured speeds, and the higher average work at 180°/s and 240°/s in relation to defenders and midfielders. The strikers presented higher average work at 240°/s in relation to midfielders, and higher PT in relation to the defenders and midfielders. Absolute values. were shown and reference values were established. Conclusions: The goalkeepers and strikers were the players that showed the greatest differences in their favor in relation to the other positions. The peak torque values and average work were described in relation to the player’s position on the field. This study resulted in the creation of a tool for health professionals working with professional soccer players, providing reference values for these players in relation to their position on the field that can be used as benchmarks, by health professionals, to optimize soccer players’ performance

El objetivo de este estudio fue describir los valores normativos musculares de cuádriceps e isquiotibiales en jugadoras profesionales de fútbol y para examinar las diferencias entre la pierna dominante y la pierna no dominante. Se utilizó un protocolo de contracción concéntrica/concéntrica bilateral estandarizado a velocidades bajas (60°/s), medias (180°/s) y altas (240°/s), realizadas en movimientos de flexión y extensión de rodilla en un rango útil de movimiento entre 0 y 90° de flexión de rodilla utilizando el sistema isocinético de dinamómetro (IsoMEd 2000). Todas los participantes eran futbolistas profesionales sanas de equipos españoles de primera y segunda división. Se evaluaron valores de Peak Torque (PT), el ratio H:Q, el PT promedio, el PT normalizado por peso, el trabajo máximo, el trabajo máximo normalizado por peso, el trabajo promedio, el trabajo total, la potencia máxima, el promedio de la potencia, el ángulo del PT y la repetición de la serie en la que el PT se producía. El presente estudio puede ser una herramienta que los profesionales de la salud que trabajan con jugadoras de fútbol profesional a su cargo pueden utilizar para evaluar y monitorear a una jugadora en particular.